Is the Internet a threat to television? Or a boon? After all, it takes a World Wide Web of computers to keep the plot of "24: Live Another Day" (9 p.m., Fox, TV-14) straight.

As a new "hour" opens, President James Heller (William Devane) prepares his address to the British Parliament. His friendship visit to the sceptered isle has soured after a drone, commandeered by a terrorist hacker, attacked a squad of allied soldiers in Afghanistan, several Britons among them.

It's a rough day for Heller, who has been part of "24" since Day 4, or Season 4. He and his daughter, Audrey (Kim Raver), have faced a lot. Audrey has loved, hated, feared, mourned and felt betrayed by Jack Bauer any number of times -- ordeals that sent Audrey over the deep end. Now she's better and married to the president's chief of staff, Mark Boudreau (Tate Donovan), who hates and fears Bauer. He also doesn't think President Heller is up to the job since showing signs of dementia. He's particularly concerned about the president's address to Parliament, where opposing backbenchers are free to heckle, jeer and ask tough questions.

Presidents have had a rough time on "24"! At least two have been betrayed by their wives. William Devane, perhaps best known for his role on "Knots Landing," has been playing presidents for the past 40 years. He played John F. Kennedy in the 1974 made-for-television movie "The Missiles of October." That was about a real president handling a real crisis when the world came very close to nuclear war. But that seems to happen every day on "24."

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Motorcycle buffs are given five weeks to cobble together their dream machines on the new series "#BikerLive" (10 p.m., Discovery, TV-PG). Every week the series will introduce new teams of bike builders and invite viewers to vote for their favorites via Twitter. Winners will be announced at the end of every show.

Social media offers Discovery a different way to revive an old genre. "Monster Garage" ran from 2002-7 on Discovery, and "American Chopper" aired on Discovery from 2003-7 before moving to TLC and fizzling out.

It should be interesting to see how hashtags go over with the bike-building crowd.

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The documentary "Let the Fire Burn" on "Independent Lens" (10 p.m., PBS, TV-PG, check local listings) revisits the disastrous 1985 effort to dislodge a black revolutionary group called "MOVE" from its Philadelphia enclave. An ensuing fire resulted in the death of 11 people, including five children.

A race to find the Suvek on "Star-Crossed" (8 p.m., CW, TV-PG).

Berlin and the bitter end on "The Blacklist" (10 p.m., NBC, TV-14).

An oft-postponed trip down the aisle nears on "Castle" (10 p.m., ABC, TV-PG).

Semifinalists perform on "The Voice" (8 p.m., NBC, TV-PG).

A man with two identities dies but once on "Bones" (8 p.m., Fox, TV-14).

The secretary of the Navy is wiretapped on "NCIS" (10 p.m., CBS, r, TV-14).

"Hotel Impossible" (10 p.m., Travel, TV-PG) visits Italy.

On two episodes of "Louie" (FX, TV-MA): a plus-sized problem (10 p.m.), a neighbor in need (10:30 p.m.).

After a vicious attack by mobsters leaves him without a voice, a popular crooner (Frank Sinatra) falls into alcoholism and then rehabilitates as a comedian in the 1957 biopic "The Joker is Wild" (8 p.m., TCM), co-starring Mitzi Gaynor, Jeanne Crain, Eddie Albert and Jackie Coogan.